Development has been made in recent years for identifying a congestion state and the like, for example, by analyzing video captured by a security camera or the like, in video surveillance and the like. For example, PTL 1 discloses a congestion estimating device which is capable of determining whether or not there is a person in each area by determining whether or not there is motion in each partial area of an input image and determining, on the basis of texture information, whether or not there is a person in each partial area.
In addition to the above, PTLs 2 to 4 also disclose related techniques.